Fission spectrum neutrons for cross section validation and neutron flux transfer

Conference · Wed Oct 01 04:00:00 EDT 1975 · Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States)

OSTI ID:7364974

Grundl, J A; Eisenhauer, C M

A variety of measurement methods over more than two decades provides a base for proper evaluation of the fission spectrum shape. The evaluation presented recommends a Maxwellian reference description for /sup 252/Cf (spontaneous fission) and /sup 235/U (thermal-neutron-induced fission) with average energy parameters of 2.13 MeV and 1.97 MeV respectively over the energy range 0.25 to 8 MeV. A further multigroup summary of the experimental data presents the final evaluation as an empirical adjustment of Maxwellian segments and includes an estimate of credible departures from the true spectrum shape. The reference Maxwellian shapes differ from the final evaluated shape by less than or equal to 2 percent over the above energy range. A few basic integral quantities, fission neutron age in water and the fission-spectrum-averaged fission cross section for /sup 238/U, /sup 235/U and /sup 237/Np, are reviewed briefly, based on the results of the evaluation. Two features of fission neutrons make them a useful reference for certain measurement problems in nuclear technology: the fission spectrum shape is preserved above approximately 1 MeV in important reactor-associated neutron environments, and small, intense sources of pure /sup 252/Cf fission neutrons are now available. A restricted class of related applications using fission neutron sources is discussed. 5 tables, 1 figure. (auth)

• Research Organization: National Bureau of Standards, Washington, DC
• OSTI ID: 7364974
• Conference Information: Journal Name: Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States) Journal Volume: 1
• Country of Publication: United States
• Language: English

Related Subjects

652026* -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYON REACTIONS
BARYONS
BOLTZMANN STATISTICS
CALIFORNIUM 252
CALIFORNIUM ISOTOPES
CROSS SECTIONS
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
FERMIONS
FISSION
FISSION NEUTRONS
HADRON REACTIONS
HADRONS
HEAVY NUCLEI
ISOTOPES
NEUTRON FLUX
NEUTRON REACTIONS
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
RADIATION FLUX
RADIOISOTOPES
SPONTANEOUS FISSION
TARGETS
THERMAL FISSION
URANIUM 235 TARGET
YEARS LIVING RADIOISOTOPES